131 lines
3.3 KiB
Groff
131 lines
3.3 KiB
Groff
.\" -*- nroff -*-
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.\"
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.\" Copyright (c) 1996 Doug Rabson
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.\"
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.\" All rights reserved.
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.\"
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.\" This program is free software.
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.\"
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.\" Redistribution and use in source and binary forms, with or without
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.\" modification, are permitted provided that the following conditions
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.\" are met:
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.\" 1. Redistributions of source code must retain the above copyright
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.\" notice, this list of conditions and the following disclaimer.
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.\" 2. Redistributions in binary form must reproduce the above copyright
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.\" notice, this list of conditions and the following disclaimer in the
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.\" documentation and/or other materials provided with the distribution.
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.\"
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.\" THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY EXPRESS OR
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.\" IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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.\" OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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.\" IN NO EVENT SHALL THE DEVELOPERS BE LIABLE FOR ANY DIRECT, INDIRECT,
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.\" INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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.\" DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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.\" THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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.\"
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.\" $FreeBSD$
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.\"
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.Dd July 24, 1996
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.Os
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.Dt VOP_LINK 9
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.Sh NAME
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.Nm VOP_LINK
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.Nd create a new name for a file
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.Sh SYNOPSIS
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.In sys/param.h
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.In sys/vnode.h
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.Ft int
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.Fn VOP_LINK "struct vnode *dvp" "struct vnode *vp" "struct componentname *cnp"
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.Sh DESCRIPTION
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This links a new name in the specified directory to an existing file.
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.Pp
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Its arguments are:
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.Bl -tag -width 8n
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.It Ar dvp
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the vnode of the directory
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.It Ar vp
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the vnode of the file to be linked
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.It Ar cnp
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pathname information about the file
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.El
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.Pp
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The pathname info must be released on exit.
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The directory and file vnodes should NOT be released on exit.
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.Sh LOCKS
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The directory,
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.Fa dvp
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is locked on entry and should remain locked on return.
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The file
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.Fa vp
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is not locked on entry and should remain that way on return.
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If your VOP code locks
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.Fa vp ,
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it must be sure to unlock prior to returning.
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.Sh RETURN VALUES
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Zero is returned if the file was linked successfully, otherwise an
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error is returned.
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.Sh PSEUDOCODE
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.Bd -literal
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int
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vop_link(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
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{
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int error = 0;
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if (vp->v_mount != dvp->v_mount) {
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error = EXDEV;
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goto out2;
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}
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if (vp != dvp && (error = VOP_LOCK(vp))) {
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goto out2;
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}
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/*
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* now that we've locked vp, we have to use out1 instead of out2
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*/
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if (vp would have too many links) {
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error = EMLINK;
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goto out1;
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}
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if (vp is immutable) {
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error = EPERM;
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goto out1;
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}
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/*
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* Increment link count of vp and write back the on-disc version of it.
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*/
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...;
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if (!error) {
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/*
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* Add the new name to the directory.
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*/
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...;
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}
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free(cnp->cn_pnbuf, M_NAMEI);
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out1:
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if (vp != dvp)
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VOP_UNLOCK(vp);
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out2:
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return error;
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}
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.Ed
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.Sh ERRORS
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.Bl -tag -width Er
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.It Bq Er EPERM
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the file is immutable
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.El
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.Sh SEE ALSO
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.Xr vnode 9 ,
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.Xr vn_lock 9
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.Sh AUTHORS
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This man page was originally written by
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.An Doug Rabson .
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